In the polishing and cleaning of semiconductor wafers, there is known a certain type of brush cleaning tool which uses a pair of rotating sponge brushes as described in Gill, Jr.'s U.S. Pat. No. 5,144,711. Such a cleaning tool is offered commercially by Westech Systems as their model 3800 Automated Wafer Cleaner. Andros, U.S. Pat. No. 5,311,634 also teaches a form of rotary brush cleaner.
It is well known in the CMP technology to provide for the cleaning of semiconductor wafers following a CMP process, see for example Blackwell, U.S. Pat. No. 5,320,706 for a general teaching of the use of a cleaning process.
It is also well know to provide for the conditioning of a polishing pad in situ during the actual polishing process as evidenced by reference to Bombardier et al. U.S. Pat. No. 5,154,021 which teaches the conditioning of a polishing pad by the application of compressed air to the pad prior to its contact with the work piece and Prigge et al. U.S. Pat. No. 5,167,667 which teaches the application of a liquid for treating a polishing cloth following the completion of a polishing process.
The IBM Technical Disclosure Bulletin, "Water/Air Brush for Wafer Chem-Mech Polishing," Vol. 37, No. Mar. 03, 1994, p. 345, shows an in situ polishing and conditioner tool in which an air brush and hot water dispenser are placed on the polishing pad while the wafer/work piece is being polished.
In the processing of semiconductor wafers using a rotating brush tool of the Gill/Westech type following the CMP planarization of polysilicon filled trenches, residual particles were found to cause rejects of product due to the presence of foreign material (FM).
Accordingly, it is an object of this invention to reduce the FM present after polishing semiconductor wafers while cleaning them with a rotary brush cleaner.
It is another object to increase the throughput of wafers cleaned after being polished by speeding up the cleaning process.